TW201251517A - Systems and methods for buffer gas flow stabilization in a laser produced plasma light source - Google Patents

Abstract

An extreme-ultraviolet (EUV) light source comprising an optic, a target material, and a laser beam passing through said optic along a beam path to irradiate said target material. The EUV light source further includes a system generating a gas flow directed toward said target material along said beam path, said system having a tapering member surrounding a volume and a plurality of gas lines, each gas line outputting a gas stream into said volume.

Description

201251517 • VI. Description of the invention: [Technical Fields of the Invention] Cross-Reference to Related Applications This application claims priority to U.S. Patent Application Serial No. 13/156,188, filed on Jun. The title is "SYSTEMS AND METHODS FOR BUFFER GAS FLOW STABILIZATION IN A LASER PRODUCED PLASMA LIGHT SOURCE", attorney docket number: 2010-0020-01, the entire contents of which is incorporated herein by reference. Field of invention

This application relates to an extreme ultraviolet ("EUV") source for providing plasma generated from a raw material and for collecting and directing EUV light to an intermediate position for EUV.

_ I source outdoor 'for example, lithography technology for manufacturing semiconductor integrated circuits at a wavelength of about 100 nm or less. C Prior Art 1 Background of the Invention Extreme ultraviolet ("EUV") light, for example, has a wavelength of about 5 to 100 nm Meters or shorter electromagnetic radiation (sometimes referred to as soft x-rays), as well as light having a wavelength of about 13 nm, can be used in lithography processes to produce very small features in substrates (eg, germanium wafers). Methods of producing EUV light include, but are not necessarily limited to, conversion of the target into a plasma state with elements (e.g., germanium, lithium, or tin) using an emission line in the EUV range. In one such method, 'often referred to as laser-generated plasma method ("LPP"), irradiating a target with a 201251517 laser beam produces the desired plasma, for example in the form of droplets, streams or The material of the cluster. In this regard, there are several advantages to the C02 laser outputting light having a mid-infrared wavelength (i.e., a wavelength between about 9.0 micrometers and 11.0 micrometers) as an irradiation target in the LPP process. . This is especially true for certain I materials, such as tin-containing materials. For example, one of the advantages is the ability to produce relatively high conversion efficiencies between driving laser input power and rotating EUV power. In the case of the LPP process, the plasma is typically produced in a sealed container (e.g., a vacuum chamber) and monitored with various types of metering equipment. In addition to producing EUV radiation, the plasma process typically also produces undesirable by-products in the plasma chamber, which can include dispersed residues of heat, high energy ions, and plasma formers, for example, not fully ionized during plasma formation. Bulk/microdroplets of raw material vapor and/or raw materials. Unfortunately, plasma formation by-products are likely to damage or reduce the operational efficiency of various plasma chamber optics including, but not limited to, reflections including multilayer mirrors (MLM) capable of reflecting EUV at normal incidence and/or tangential incidence. The mirror, the surface of the metrology detector, the window used to visualize the plasma formation process, and the laser input light (eg, can be a window or a focusing lens). Thermal, energetic ions and/or raw material residues can damage the optical components in a number of ways, including heating them, coating them with light transmissive materials, infiltrating them, for example, and damaging structural integrity and/or optical properties, For example, mirrors reflect the ability to have such short wavelengths of light, corrode or erode them and/or diffuse into them. It has been suggested to use buffer gases such as hydrogen, helium, argon or their 201251517, 'and two. The buffer gas may be present in the chamber during plasma generation and may be used to slow down the generation of ions by the electric name to reduce the deterioration of the optical member and/or increase the plasma efficiency. For example, in the space between the plasma and the light member, electricity may be supplied. The ions produced by the slurry are sufficient to reduce their ion energy to a buffer gas pressure of about _ or less before reaching the surface of the light member. In some implementations, one or more pumps may be used to allow the buffer gas to enter and exit the vacuum. Suitable for heat, steam, cleaning reaction products and/or particles to be removed from the vacuum chamber. The exhaust gas may be discarded, or in some cases, the gas may be treated 'eg, transition, cool, etc., and the n-stream may be used to direct the particles away from critical surfaces such as mirrors, lenses, windows, detectors, and the like. . At this point, turbulence characterized by turbulent eddies (which can be swirled with fluid and countercurrent) is undesirable because they can include flow toward critical surfaces. Countercurrent flow can add surface deposits by transporting materials to critical surfaces. Turbulence may also destabilize the target droplets in a random manner. In general, this instability is not easily compensated, and as a result, the accurate radiography of the light source may have an adverse effect on the performance of the small target droplets. It has been suggested to use one or more chemical species that chemically interact with the deposited material in the LPP source to remove deposits of the optical member. For example, it has been disclosed to use a halogen containing a compound (e.g., methyl bromide, vapor, etc.). One of the potential cleaning techniques involves the use of tin when the plasma target contains tin.

I Hydrogen radicals remove tin and tin-containing deposits from the light. In a mechanism, a hydrogen radical combines with the deposited tin to form a hydrogen hydride vapor which can then be removed from the vacuum chamber. However, for example, if the countercurrent generated by the turbulent vortex flows backward toward the surface of the optical member, the hydrogen hydride vapor may be decomposed to redeposit the tin. Next, 201251517 this means that the flow that is directed away from the surface of the light member reduces turbulence (and, if possible, laminar flow), by reducing the redeposition by cleaning the reaction product decomposition. SUMMARY OF THE INVENTION Based on the above considerations, the applicant of the present invention discloses a system and method for stabilizing buffer flow in a laser generated plasma source. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a simplified schematic diagram of an EUV source coupled to an exposure apparatus having a system for directing airflow around the optical element generally along the beam path and toward the irradiation zone while maintaining the gas in a substantially turbulent state. Figure 2 illustrates in greater detail the enlarged portion of the display airflow system in the EUV source of Figure 1; the simplified schematic of Figure 3 illustrates another embodiment of the airflow system with the shield; Figure 4 A simplified schematic diagram illustrates another embodiment of the airflow system and has a plurality of flow guides that extend into the airflow by the tapered members; Figure 5 is depicted along line 5-5 of Figure 4 to illustrate Cross section of the flow guide and the gas line; Fig. 5A is a cross section taken along line 5-5 of Fig. 4 to illustrate an alternative configuration of the flow guide and the gas line; Another embodiment of the airflow system has a shroud and a plurality of flow guides that extend into the airflow from the shroud; Figure 7 is drawn along line 7-7 of Figure 6 to illustrate the flow. Cross section of the guide, its system; and 2012515 17 is a simplified schematic view of another embodiment of the airflow system with tapered members for smoothing the sharpness of the cylindrical housing: L. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a simplified schematic cross-sectional view of a selected portion of an Euv lithography apparatus not shown by the symbol 10 in accordance with one aspect of the specific embodiment. For example, device 10 may expose a substrate with a patterned beam of Ευν light, such as a wafer plate workpiece coated with a resist, or the like. As for device 10, an exposure device 12 utilizing EUV light (eg, integrated circuit lithography tools, steppers, scanners, step and scan systems, direct write systems, devices that use contacts and/or proximity masks, etc.) Alternatively, more light members may be provided, for example, to illuminate the patterned light member, such as a diaphragm, to produce an ear pattern beam, and one or more reduced projection light members for projecting the patterned beam onto the substrate. A mechanical assembly for producing controlled relative motion of the substrate and the patterned member can be provided. The term 'lighting element' (〇ptiC), as used herein, and its derivatives include, but are not necessarily limited to, one or more components that reflect and/or transmit and/or manipulate incident light 'including but not limited In: one or more lenses, windows, ferrites, commutators, crucibles, grations, grading, transmission optics, standard gauges (etalon), diffusers, homogenizers, detectors, and Other instrument group

I-piece, open-hole, axicon, and mirror, including multilayer mirror, near-normal incidence mirror, grazing incidence mirror, specular reflector, 7 201251517 Diffuse reflectors and combinations of them. Moreover, unless otherwise stated, the term "light member," or a derivative thereof, as used herein, is not intended to be limited to a separately operated component or advantageous in one or more particular wavelength ranges, such as EUV output light wavelength, irradiation. Laser wavelength, suitable for measuring the wavelength of the wavelength or some other wavelength. Figure 1 illustrates a particular embodiment in which the apparatus 10 includes an LPP source 2 for generating EUV light for exposing the substrate. As shown, System 2i is used to generate a sequence of light pulses and to deliver light pulses into source chamber 26. For device ίο, light pulses can travel along system one or more beam paths 27 from system 21 and into chamber 26 to illuminate the irradiation region. One or more targets of 48 to produce an EUV light output for exposing the substrate in exposure apparatus 12. The appropriate laser for system 21 illustrated in Figure 1 may include a pulsed laser attack, for example, with DC or RF excitation, with relatively high power (eg, 1 〇 read or higher) and high pulse repetition rate (eg, 40 kHz or greater) operation produces 9 to " micron light pulsed gas discharge C 〇 2 Ray Shooting device. In a specific implementation, The laser can be an axial-flow RF-pumped C〇2 laser with multiple amplification stages of the oscillator-amplifier configuration (eg, main oscillator/power amplifier (M〇pA) or power oscillator/power Amplifier (P0PA)), and a 9-switched oscillator initialized with a relatively low energy and high repetition rate to a seed pulse that can operate, for example, at 1 kHz (seed pulsed, then the laser pulse from the oscillator reaches the irradiation Zone 48 can be magnified, shaped, and/or focused before. Continuously pumped c〇2 amplifiers can be used in laser system 21. For example, there are oscillators and three amplifiers (0-PA1-PA2-PA3 configuration) A suitable C〇2 laser device is disclosed in U.S. Patent Application Serial No. 11/174,299, filed on Jun. 29, 2005, entitled, PCT, PCT, PCT, 01, at this time, U.S. Patent No. 7,439,530, issued Oct. 21, 2008, the entire disclosure of which is incorporated herein in The droplets are used as a mirror in the optical cavity. Some "self-calibration," configurations may not require an oscillator. There are several self-calibrated laser systems disclosed and claimed in US Patent Application Serial No. 11/580,414 (Application on October 13, 2006) titled DRIVE LASER DELIVERY SYSTEMS FOR EUV LIGHT SOURCE, attorney file number: 2006-0025-01, at this time, U.S. Patent No. 7,491,954, issued Feb. 17, 2009, the entire disclosure of which is incorporated herein by reference. Other types of lasers are also suitable depending on the application, for example, excimer or molecular fluorine lasers operating at high power rates and high pulse repetition rates. Other suitable embodiments include, for example, solid state lasers having fibers, rods, slats, or disc-shaped active media, one or more chambers (eg, an oscillator chamber with one or more parallel or series amplifications) Other laser architectures, main oscillator/power oscillator (ΜΟΡΟ) configuration, main oscillator/power loop amplifier (MOPRA) configuration' or with one or more excimer, molecular fluorine or c〇2 amplifier or oscillation The chamber is a solid-state laser for seeding. Other designs may be suitable. In some cases, the target may first be pre-pulse (pre*pulse) and then irradiated with the main pulse. The pre-pulse and main pulse seeds can be generated with a single oscillator or two independent oscillators. In some settings, one or more shared amplifiers can be used to amplify the pre-pulse seed and the main pulse seed. For other configurations, a separate amplifier can be used to amplify the pre-pulse and main pulse seeds. For example, the 201251517 seed laser can be a C〇2 laser that uses a radio frequency (RF) discharge to pump a sealing gas containing c〇2 below atmospheric pressure (eg, 0 05_02 atmospheric pressure). With this configuration, the seed laser can self-tune to one of the main lines', for example, a 1 〇Ρ (2 〇) line having a wavelength of 10_591 〇 352 μm. In some cases the 'Q switch can be used to control the seed pulse parameters. The s-channel amplifiers can have two or more amplification units each having its own chamber, working medium, and excitation source (e.g., pumping electrodes). For example, as described above, where the seed laser includes a gain medium containing C 〇 2, a suitable laser for use as an amplifying unit may comprise a working medium containing C 〇 2 gas pumped by DC or RF excitation. In a particular implementation, the amplifier can include a plurality (eg, 3 to 5) of axial flow RF pumped (continuous or pulsed) c〇2 amplification units having a total gain length of about 10 to 25 ohms. Rulers, and operate together at relatively high power (eg, 10 kW or higher). Other types of amplification units can have slat geometry or coaxial geometry (for gaseous media). In some cases, solid working media using rod or disc shaped gain modules or fiber based gain media may be utilized. The laser system 21 can include a beam conditioning unit for one or more optical components for beam conditioning, such as expansion, manipulation, and/or shaping between the laser source system 21 and the irradiation site 48. beam. For example, the steering system (which may include one or more mirrors, cymbals, lenses, space filters, etc.) may be mounted and configured to manipulate the laser focus at different locations in the chamber 26. In an arrangement, the steering system can include a first flat mirror and a second flat mirror, the first flat mirror being mounted on a tilt-tilt actuator that can independently move the first flat mirror in two dimensions And the second mirror is mounted on a deflection tilt actuator that can independently move the second mirror in two dimensions. 201251517 • With this configuration, the interpolating system month b controllably moves the focus in a direction substantially orthogonal to the direction of propagation of the beam. A focus assembly can be provided to focus the beam onto the irradiation site 48 and to adjust the position of the focus on the optical axis. As for the focus assembly, a light member 50, such as a focusing lens or mirror, can be used that is coupled to an actuator 52 (shown in Figure 2) that moves along the optical axis, such as a stepper motor, a servo motor, Piezoelectric transducers and the like to move the focus on the optical axis. In one configuration, the optical member 50 can be a 177 mm lens made of optical grade zinc selenide (ZnSe) and a transparent opening of about 135 mm. With this configuration, it is convenient to focus a light beam having a diameter of about 120 mm. The following documents provide additional details relating to the beam conditioning system: U.S. Patent Application Serial No. 10/803,526, filed on March 17, 2004, entitled A HIGH REPETITION RATE LASER 'PRODUCED PLASMA EUV LIGHT SOURCE, attorney file number: 2003-0125-01, at this time, U.S. Patent No. 7,087,914, issued August 8, 2006; U.S. Serial No. 10/900,839, filed on July 27, 2004, entitled EUV LIGHT SOURCE, attorney file number: 2〇〇4-〇〇44-〇1, at this time, US Patent No. 7,164,144, published on January 16, 2007, and applied for December 15, 2009. U.S. Patent Application Serial No. 12/638,092, entitled: BEAM TRANSPORT SYSTEM FOR EXTREME ULTRAVIOLET LIGHT S0URCE 'Attorney Docket No.: 2009-0029-01, the entire contents of which is incorporated herein by reference. As shown in Figure 1, the EUV source 20 can also include a target delivery system 90, such as an irradiation zone that delivers droplets of a target (e.g., tin) into the interior of the chamber 26 201251517

48, where the droplets interact with one or more light pulses, for example, zero, one or more pre-pulses from system 21 and then one or more main pulses to ultimately produce plasma and generate EUV radiation to The exposure device 12 exposes a substrate, such as a resist coated wafer. Further details and relative advantages associated with the configuration of various droplet dispensers can be found in the following: US Patent Application Serial No. 12/721,317, filed on March 10, 2010, and on November 25, 2010, US 2010/0294953A1 is published under the heading LASER PRODUCED PLASMA EUV LIGHT SOURCE, attorney file number: 2〇08-0〇55·01; US Patent No. 12/214,736, filed on June 19, 2008, September 2009 Published on the 17th as 11.3.2009/〇230326 八1, titled SYSTEMS AND METHODS FOR TARGET MATERIAL DELIVERY IN A LASER PRODUCED PLASMA EUV LIGHT SOURCE, attorney file number: 2006-0067-02; application on July 13, 2007 U.S. Patent Application Serial No. 11/827,803, issued Jan. 15, 2009, to US-A-2009-0014668A1, entitled LASER PRODUCED PLASMA EUV LIGHT SOURCE HAVING A DROPLET STREAM PRODUCED USING A MODULATED DISTURBANCE WAVE, Lawyer File Number: 2007-0030 -01; US Patent Application Serial No. 11/358,988, filed on Feb. 21, 2006, entitled LASER PRODUCED PLASMA EUV LIGHT SOURCE WITH PRE-PULSE, Lawyer Case Number U.S. Patent Application Serial No. 11/067,124, filed on Feb. 25, 2005, entitled, s s s s s s s s s s s s s s s s s s s s s s s s s s s s s s s s s s s s s s s s s s s s s s EUV PLASMA SOURCE TARGET DELI VERY 'Attorney's Archives No.: 2004-0008-01; this time is US Patent No. 7,405,416, issued July 29, 2008; and US Patent Application Serial No. on June 29, 2005 No. 11/174,443, entitled LPP EUV PLASMA SOURCE MATERIAL TARGET DELIVERY SYSTEM 'Attorney's File No.: 2005-0003-01, at this time, US Patent No. 7,372,056, published on May 13, 2008; This article is included as a reference. The target may include, but is not necessarily limited to, a material comprising tin, lithium, ruthenium or a combination thereof. EUV radiation elements (e.g., tin, lithium, cesium, etc.) can be in the form of liquid droplets and/or containing solid particles within the liquid droplets. For example, elemental tin can be used as pure tin as a tin compound (eg, SnBr4, SnBr2, SnH4) as a tin alloy (eg, tin-gallium alloy, tin-indium alloy, tin-indium-gallium alloy, or a combination thereof). ). Depending on the materials used, the dry material can be present in the irradiation zone 48 at various temperatures, including room temperature or near room temperature (eg, tin alloy, SnBr4), elevated temperature (eg, pure tin), or below room temperature. The temperature (for example, SnH4), and in some cases, the relative volatility, for example, SnBr4. Materials for use with LPPEUV light sources are provided in more detail in U.S. Patent Application Serial No. 11/406,216, filed on Apr. 17, 2006, entitled ALTERNATIVE FUELS FOR EUV LIGHT SOURCE, attorney file number · 2006- 0003-01, this time is public

I, U.S. Patent No. 7,465,946, issued Dec. 1, 2008, the disclosure of which is incorporated herein by reference. With continued reference to FIG. 1, device 10 may also include EUV controller 60, which may also include 201251517, which may include a laser control system 65 for triggering power input to one or more gain modules in system 21 (eg, RF generation) The lamp and/or other laser device thereby generating a pulse of light for delivery into the chamber 26 and/or for controlling the movement of the light member in the beam conditioning unit. Device 10 may also include a droplet position sensing system that may include one or more droplet imagers 70 for providing an output indicative of the position of one or more droplets relative to, for example, irradiation zone 48. The (equal) imager 70 can provide such output to the droplet position detection feedback system 62 which can, for example, calculate the droplet position and trajectory to calculate the droplet error, e.g., on a droplet by drop or average basis. A droplet error can then be provided as an input to the controller 60, for example, the controller 60 provides position, direction, and/or timing correction signals to the system 21 to control the source sequential circuitry and/or to control the light components in the beam steering unit. The motion 'for example, is used to change the focus position and/or the focus power of the light pulse being delivered to the light-sensitive area 48 in the chamber 26. Moreover, for EUV light source 20, dry material delivery system 90 can have a control system operative to respond to signals from control benefit 60 (in some implementations, the above-described droplet error or its number of occurrences can be included), For example, the error of the droplets reaching the desired (four) region 48 is corrected by modifying the release point, release timing, and/or droplet modulation. With continued reference to FIG. 1, device 10 may also include a light member 24, such as a near vertical/echo wire mirror having a reflective surface of a shaped sphere (ie, an ellipse that is rotated about a major axis). For example, there are alternating multi-layer coatings, and in some cases, one or more high temperature diffusion barrier layers, smoothing layers, cover layers, and/or surface stop layers. FIG. 1 illustrates a light member 24 that may be formed with apertures to allow light pulses generated by system 21 to pass through and reach irradiation zone 48. As illustrated in FIG. 14 201251517, the light member 24 can be, for example, a long ellipsoid mirror having a first focus in or near the irradiation zone 48 and a second focus in the so-called intermediate zone 4 在 where EUV light can be emitted by the EUV light source 20 The output and input are to an exposure device 12 that utilizes light, such as an integrated circuit lithography tool. A temperature control system can be placed on or near the back side of the light member 24 to selectively heat and/or cool the light member 24. For example, temperature control system 35 (shown in Figure 2) can include conductive blocks that are formed with channels to allow heat transfer fluid to circulate. It will be appreciated that other light elements can be used in place of the long ellipsoidal mirror to collect and direct light to an intermediate position for subsequent delivery to a device that utilizes EUV light. For example, the light member can be a parabolic object that is rotated about a long axis. Or can be configured to deliver a beam having a circular cross-section to an intermediate position, for example, in U.S. Patent Application Serial No. 11/505,177, filed on Aug. 16, 2006, which is hereby incorporated by reference. U.S. Patent No. 7,843,632, entitled EUV OPTICS, attorney Docket No.: 2006-0027-01, the contents of which is incorporated herein by reference. With continued reference to Figure 1, gas 39 can be introduced into chamber % via lines i〇2a, b as shown. The figure also shows that 'the guideable gas 39 bypasses the light member 50 in the direction of the arrow 1〇4, through the opening forming the light member 24 so as to flow substantially along the beam path 27 and toward the irradiation in the direction of the arrow 106. District 48. With this configuration, the flow of the gas 39 can reduce the flow/diffusion of the residue generated by the plasma in the direction from the irradiation site to the light member 24, and in some cases, can advantageously transport the reaction product of the surface of the cleaning light member 24. For example, tin hydride prevents them from decomposing and redepositing the material back onto the surface of the light member. In some implementations, the gas 39 may comprise a buffer gas for ion mitigation, such as hydrogen, helium, argon or a combination thereof, a purge gas, such as a gas containing the element 15 201251517, and/or may react to produce a cleaning material. gas. For example, the gas may comprise hydrogen or hydrogen-containing molecules that can react to produce a hydrogen radical cleaning material. As detailed below, gases having the same or different composition as gas 39 can be introduced into other locations in chamber 39 to control flow pattern and/or gas pressure' and can be pumped via one or more pumps (eg, pump 41a) , b) removing the gas in chamber 26. The gas may be present in chamber 26 during plasma discharge and may be used to slow plasma generation of ions to reduce optical degradation and/or improve plasma efficiency. Alternatively, a magnetic field (not shown) may be used alone or in combination with a buffer gas ' to reduce the destruction of fast ions. Furthermore, the depletion/supplement of buffer gas may be used to control the temperature, for example, to remove heat or cooling chamber % of chamber 26 One or more components or light components. In one configuration, 'the closest distance d' between the optical member 24 and the irradiation region 48 can cause the buffer gas to flow between the plasma and the optical member 24 to establish a gas density level that is still sufficiently operable at a distance d and to make electricity. The kinetic energy of the ions produced by the slurry drops to a level below about i〇〇ev before the ions reach the optical member 24. This can reduce or eliminate damage caused by the ions of the optical member 24 generated by the plasma.

The pumps 41a, b can be turbopumps and/or roots blowers. In some cases, the recoverable exhaust gas returns to the unit 1 〇. For example, a closed loop flow system (not shown) can be used to return the exhaust gases to the unit. The closed loop may contain one or more filters, heat exchangers, resolvers (e.g., tin hydride decomposers) and/or pumps. Further details relating to the closed-loop flow path can be found in US Patent No. 7,655,925, issued Feb. 2, 2010, entitled GAS MANAGEMENT SYSTEM FOR A LASERrPRODUCED-PLASMA EUV LIGHT SOURCE, attorney case number: 2007-0039 -01; and the application of International Patent Application No. 16 201251517, No. PCT/EP10/64140, entitled SOURCE COLLECTOR APPARATUS LITHOGRAPHIC APPARATUS AND DEVICE MANUFACTURING METHOD, attorney file number: 2〇10-0〇22- 〇 2' The above contents are incorporated herein by reference. As can be seen from Fig. 2, a taper member 100 having an enclosure volume of 15 可 can be mounted. Further, as shown, a plurality of gas lines 1〇2a, b can be arranged to output a gas stream entering the volume 150. Once in the volume 〇5〇, the flow is bypassed by the taper member 100 (the focus lens in the illustrated embodiment) to produce a permeate, turbulent flow through the aperture 15 formed in the light member 24. 2 and generally flow along beam path 27 and flow in the direction of arrow 丨〇6 to Korean leg 48. For some airflows, the operable surface of the tapered member can be smoothed or otherwise prepared as a removable burr, a broken sharp edge, and a surface having a surface area of no more than 1 exposure, preferably no more than about two meters. . In the configuration, a flow of gas along the beam path toward the dry material is produced, and the system can flow a nitrogen size greater than (10) standard cubic liters (▲) per minute.

, TH, TD, 02 and D). Figure 3 illustrates the generation of a gas stream which is bypassed by a light member 5 (in the embodiment, a focusing lens) and along a thunder

The tapered member 100 is configured to illustrate a specific laser beam path 27 toward the irradiation zone. The system can include a surrounding gas volume 150 that can output a gas stream into the volume 150. 201251517 multiple gas lines l〇2a, b. For the configuration of Figure 3, the shield 200 can be disposed in the aperture 152 of the light member 24 and positioned to extend from the aperture 152 to the irradiation zone 48. The shield 200 can be pointed in a direction toward the irradiation zone 48 and, in some cases, can be cylindrical. The shield 200 can be used to reduce debris flowing into the volume 150 from the irradiation zone 48 where it can be deposited on the light member 50 and/or can be used to direct or flow gas from the volume 150 to the irradiation zone 48. The shield 200 may have a length on the beam path 27 of a few centimeters to 10 centimeters or more. In use, gas can be introduced into volume 150 using gas lines 102a, b. Once in the volume 150, the flow through the optical member 50 is directed by the tapered member 100 to produce substantially no turbulent flow through the aperture 152 and the shield 200. The gas can then flow generally along the beam path 27 from the shroud 2 and into the irradiation zone 48 in the direction of arrow 1 〇6. Figure 4 illustrates another system embodiment for generating a gas stream and directing it around the light member 5 (in the illustrated embodiment, a focus lens) and along the laser beam path toward the irradiation region 48. As illustrated, the system can include a tapered member 100 surrounding a volume 15 以及 and a plurality of gas lines 102a, b configured to output a flow of gas into the volume 150. For the configurations of Figs. 4 and 5, a plurality of flow guides 30a to h may be attached to or integrally formed with the tapered member 1〇〇. As shown, each flow guide 3〇〇dh can protrude into the volume 15〇 from the inner wall of the tapered member. Although illustrated by eight flow guides, it should be understood that 'if a flow guide is used', more than eight and only one may be used. It should also be noted that some configurations (ie, the first) do not use flow guides. The flow guide can be relatively short 'for example, only affecting 1 to 5 cm' of the flow near the surface of the tapered member 1 or can be longer, and in some cases, extending to the miscellaneous recording of the light member or (4) . Face Weizhong, flow 18 201251517 - The shape of the moving guide is made to be consistent with the light cone. Figure 5A illustrates another embodiment using relatively long rectangular flow guides 300a' to c'. The flow guides may be evenly or unevenly distributed around the tapered member. In some cases, the uniform distribution can be modified to accommodate and/or smooth the flow bypassing the asymmetric sweat barrier, such as actuator 52 of Figure 2. Cross-reference to Figures 4 and 5' also shows that the plurality of gas lines 1〇2a to h can be configured to output a gas inlet volume of 15 〇. Although illustrated by eight gas lines, it should be understood that more than eight and only one can be used. The gas lines may be evenly distributed around the tapered member or the gas lines 102a' to c' may be unevenly distributed as shown in Fig. 5A. If multiple gases are used, the flow through each gas line may be the same or different from the other gas lines. In some cases, the uniform distribution of gas lines may be modified and/or the relative flow rates between the gas lines may be modified to accommodate and/or smooth the flow bypassing the asymmetric flow barrier, such as actuator 520 of FIG. In use, the gas lines 102a through h can be used to direct gas into the volume 150. Once in the volume 15 , the flow is bypassed by the tapered member 100 and the flow directors 3 〇〇 a to h to produce substantially turbulent flow through the aperture 152 and then generally flow along the beam path 27 and along The direction of the arrow 106 flows to the irradiation zone 48. Figure 6 illustrates another system embodiment for generating a gas stream and directing it around the light member 5, (in the illustrated embodiment, a window) and along the laser beam path 27 toward the irradiation region 48. For the illustrated system, the window can be installed to allow laser input from the laser system 21 to the sealed chamber 26 at noon. The lens 4 can be disposed outside of the chamber 26 to concentrate the laser to the focus in the irradiation zone. In some configurations (not shown), lens 400 can be replaced with one or more focusing mirrors, for example, and 201251517 using an off-axis parabolic mirror. As shown, the system can include a cone member 100 having a containment volume 150 and a plurality of gas lines 102a, b configured to output a gas stream into the volume 15A. For the configuration of Figure 6, the shield 200' can be disposed in the opening of the light member 24 and positioned to extend from the opening to the irradiation zone 48. The shield 200 can be pointed in the direction toward the light-sensitive area 48 and, in some cases, can be cylindrical. The shroud 200' can be used to reduce debris flowing into the volume 150 from the irradiation zone 48 where it can be deposited on the light member 50' and/or can be used to direct or flow gas from the volume 150 to the irradiation zone 48. The shield 200' may have a length on the optical axis 27 of a few centimeters to 10 centimeters or more. For the configurations of Figures 6 and 7, a plurality of flow guides 402a-d can be attached to or integrally formed with the shield 200. As illustrated, each flow guide 4〇2a to d may protrude from the inner wall of the shroud 200. Although illustrated by four flow guides, it should be understood that more than four and only one can be used if a flow guide is used. It should also be noted that some configurations (i.e., Figure 3) do not use flow guides. The flow guides can be relatively short, e.g., affecting only 1 to 5 centimeters of flow near the surface of the shroud 200, and the shroud 2〇〇 is typically designed to lie only slightly above the converging cone of light emitted by the lens 400. In some configurations, the flow guides are shaped to conform to the light cone. The flow guides may be evenly or unevenly distributed around the shroud. When in use, the gas lines l〇2a, b may be used to direct the gas into the volume 15〇. Once in the volume 15 ,, the lighter 50 is guided by the taper member 100, creating a substantial turbulent flow through the shield 2 〇 and the flow guides 242a through d while still maintaining substantial turbulence. The gas from the shroud 200 can then generally flow along the beam path 27 and flow toward the irradiation zone 48 in the direction of arrow 1 〇6. 20 201251517 Figure 8 illustrates another system embodiment for generating a gas stream and directing it around the light member 5 (in the illustrated embodiment, a focusing lens) and along the laser beam path 27 toward the light-illuminated region 48. As illustrated, the system can include a cylindrical housing 5 that encloses a volume 15 〇 and has a relatively sharp corner 502. For this air flow system, the taper member 1 〇 〇 ' can be arranged to smooth the air flow around the corner 502. Figure 8 also illustrates that gas can be introduced at other locations in chamber 26. As illustrated, a manifold 504 can be disposed about the light member 24 to provide a flow of gas along the surface of the light member 26 in the direction of arrow 506. It will be appreciated that one or more of the airflow system features of Figures 2 through 8 may be combined. For example, the flow guide 300a (Fig. 4) may use a shield 2 (Fig. 3) or a shield 2 having flow guides 402a to d and the like. Although a specific embodiment of the present invention can be fully described and illustrated in the present patent application in order to satisfy the requirements of Section 112, paragraph 35 of the U.S. Patent Law, it is possible to fully achieve one or more of the above objectives, For the sake of any other reason or the objectives of the above-described embodiments, those skilled in the art should understand that the specific embodiments are merely exemplary, illustrative, and representative of the subject matter of the invention. It is intended that the singular and singular s All of the above-described specific embodiments of the above-described embodiments, which are known to those of ordinary skill in the art, which are known to those skilled in the art, are structurally and functionally equivalent, and are hereby incorporated by reference. . All elements that are equivalent to any of the above-described embodiments (known to those of ordinary skill in the art or will be known hereinafter) in structure 21 201251517 and functionally equivalent are hereby incorporated by reference herein in The scope can cover these components. Any terms expressly used in this patent specification and/or the claims of the present application and the meaning of the present specification and/or the application of the present invention should have the meaning, regardless of any dictionary or other commonly used meanings for the term. How to explain. The apparatus or method described in this specification to describe any aspect of the specific embodiments is not intended or necessarily intended to cover each of the problems to be solved by the specific embodiments disclosed herein. . It is not intended that the elements, components, or method steps of the present disclosure be presented to the public, whether or not such elements, components, or method steps are disclosed. None of the components included in the scope of the patent application is explained under paragraph 6 of Article 112, paragraph 35 of the US Patent Law, unless the component is "a component for" or the component is a method application. Make a clear statement with “steps” instead of “acting”. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a simplified schematic diagram of an EUV source coupled to an exposure apparatus having a system for directing airflow around the optical element generally along the beam path and toward the irradiation zone while maintaining the gas substantially free. a turbulent state; Figure 2 illustrates in greater detail the enlarged portion of the airflow system of the EUV source of Figure 1; a simplified schematic of Figure 3 illustrates another embodiment of the airflow system with a shield; 4 is a simplified schematic diagram showing another embodiment of the airflow system and having a plurality of flow guides extending into the airflow by the tapered members; 22 201251517 Figure 5 is a line 5-5 along line 4 The cross section of the flow guide and the gas line is illustrated; Figure 5A is a cross section taken along line 5-5 of Fig. 4 to illustrate an alternative arrangement of the flow conductor and the gas line; A simplified schematic diagram illustrates another embodiment of an airflow system having a shroud and a plurality of flow guides that extend into the airflow by the shroud; Figure 7 is depicted along line 7-7 of Figure 6 A cross-section of the flow guides is illustrated And another simplified schematic diagram illustrating a gas flow system of the embodiment of FIG. 8, which based member having a tapered cylindrical housing for causing the sharp corners smoothed. [Main component symbol description] 10.. EUV lithography device 12.. Exposure device 20.. .LPP light source 21.. System 24, 50, 50'...light 26.. Light source chamber 27. .. laser beam path 35.. temperature control system 39...gas 40.. intermediate zone 41a, 41b...pump 48..irradiation zone 52.. actuator 60.. EUV controller 62 .. droplet position detection feedback system 23 201251517 65.. drive laser control system 70.. droplet imager 90.. target transport system 100, 100'... taper members 102a, 102b, 102a- 102h, 102a, -102c, ... gas lines 104, 106, 506... direction arrows 150.. volume 152.. openings 200, 200'... shields 300a, 300b, 300a-300h, 300a, -300c'·.. Flow Guide 400.. Lens 402a-402d···Flow Guide 500.. . Cylindrical Shell 502.. Corner 504.. Manifold 24

Claims (1)

201251517 VII. Patent Application Range: 1. An extreme ultraviolet (EUV) light source comprising: a light member; a target; a laser beam that passes through the light member along a beam path to irradiate the target And a system for generating a gas flow along the beam path toward the target, the system having a cone of material surrounding a volume and a plurality of gas lines, each gas line outputting a stream of gas into the volume. 2. The light source of claim 1, wherein the tapered member has an inner wall and further comprises a plurality of flow guides projecting from the inner wall. * 3. The light source of claim 1, wherein the light member is a window. 4. The light source of claim 1, wherein the light member is a lens that concentrates the light beam to a focus on the beam path. 5. The light source of claim 1, wherein the tapered member surrounds the beam path. 6. The light source of claim 1, wherein the gas stream comprises a gas selected from the group consisting of hydrogen (hydrogen), hydrogen (hydrogen), and hydrogen (gas). 7. The light source of claim 1, wherein the tapered member does not extend into the laser beam. 8. The source of light of claim 1 wherein the gas stream has a flow rate of more than 40 standard cubic liters per minute (sclm). 9. The light source of claim 1, further comprising a perforated 25 201251517 polar ultraviolet mirror, wherein the air flow is directed through the opening. 10. The light source of claim 1, further comprising a droplet generator for generating a stream of target droplets. 11. The light source of claim 1, wherein the light member is a lens having a diameter greater than 150 mm. 12. An extreme ultraviolet (EUV) light source comprising: a light member; a dry material; a laser beam passing through the light member to irradiate the target along a beam path; and generating a beam along the beam a system of a path toward a flow of one of the targets, the system having a tapered guide enclosing an inner wall of a volume, at least one gas line that outputs a gas stream into the volume, and a plurality of gas lines protruding from the inner wall Flow guides. 13. The light source of claim 12, wherein the light member is a window. 14. The light source of claim 12, wherein the light member is a lens θ that concentrates the light beam to a focus on the beam path. 15. The light source of claim 12, wherein the air flow has More than 40 standard cubic liters per minute (sclm) of flow. 16. The light source of claim 12, wherein the light member is a lens having a diameter greater than 150 mm. 17. A method for producing an extreme ultraviolet (EUV) light output, the method comprising the steps of: providing a light member; 26 201251517 providing a target; passing a laser beam through the light member along a beam path Radiating the target; and generating a gas flow along the beam path toward the target, the system having a tapered guide having an inner wall surrounding one of the volumes, and outputting a gas I stream into the volume at least a gas line, and a plurality of flow guides projecting from the inner wall. 18. The method of claim 17, wherein the light member is a window. 19. The method of claim 17, wherein the light member is a lens that focuses the beam onto a focus on the beam path. 20. The method of claim 17, wherein the gas stream has a flow rate of more than 40 standard cubic liters per minute (sclm) and the light member is a lens having a diameter greater than 150 mm. 27